* {
    margin: 0px;
    padding: 0px;
    font-family: "微软雅黑";
}

.container {
    background-image:  url(assert/login_bg2.jpg);
    height: 100vh;
    background-size: cover;
    background-position: center;
    /*border: 1px solid #333;*/
    /*background: url("../image/background.jpg") no-repeat;*/
}

.container::before {
    content: "";
    position: absolute;
    height: 75%;
    width: 100%;
    left: 0;
    bottom: 0;
    background: linear-gradient(to top, #000000, #00000000);
    background-size: 100% 100%;
}

#header {
    position: relative;
    /*border-bottom: 1px solid #000;*/
    height: 40px;
    /*top: -10;*/
}

#header ul {
    float: right;
    list-style: none;
    margin: 15px;
}

#header ul li {
    display: inline-block;
    padding: 10px;
}

#header ul li a {
    text-decoration: none;
    color: #fff;
    padding: 5px 30px;
    border: 1px solid transparent;
    transition: .6s ease;
    border-radius: 20px;
}

#header ul li a:hover{
    background-color: #fff;
    color: #000;
}

#header ul li.now a {
    background-color: #fff;
    color: #000;
}